The beleaguered principal of Harlow College is facing calls for his resignation following publication of the results of A-level modules that his opponents claim are "far from satisfactory".

The president of the college's students' union, Victoria Broad, maintains that large numbers of students either failed or received low grades in exams taken in January. The college is the main provider of A-level education in Harlow - only one of the six comprehensive schools in the town, a Roman Catholic school, has a sixth form.

Broad says she was among several students awarded U grades in two modules taken as part of her A-level in psychology. "We were totally unprepared for the exams," she says.

The results have provided the ammunition for Tony Edwards, a leading figure in the campaign against the leadership strategy adopted by Colin Hindmarch since his appointment as principal 18 months ago, to write an open letter calling for his sacking.

Last month Bill Rammell, the further education minister who is also MP for Harlow, issued a public condemnation of Hindmarch's reforms, which have led to the departure of more than a third of the college's teaching staff. Revealing that the cost of the restructuring totalled just under £1m, he stated in a letter sent to more than 20 campaigners: "These very high costs reinforce my view that the change strategy the principal initiated was not adequately thought through or effectively implemented."

Bereft of staff

Rammell intervened in the crisis that hit the college last summer in which large numbers of full-time staff were either made redundant or took redundancy. One departing lecturer said that it left whole departments bereft of staff.

Stressing that he was acting in his role as constituency MP and not as the further education minister, Rammell asked Essex Learning and Skills Council to review the college's introduction of a new teaching strategy. As a result, two new governors were appointed, the Quality Improvement Agency was brought in to work with Hindmarch and the management team, and inspectors from Ofsted conducted a monitoring review.

Figures vary as to the exact number of teachers who left. Ofsted said 80 of the 210 teaching staff went. The lecturers' union UCU claimed more than 100 out of 179 staff departed. Rammell put the figure at 70%, and revealed that the cost of the restructuring amounted to £819,357. Additional legal and recruitment costs of £167,000 put the total cost close to £1m.

Ofsted reported that of the 80 teachers recruited to replace them, the majority were new to teaching and many have no teaching qualifications. Inspectors said: "Staffing shortages are still evident in a few areas. As a consequence, some teaching groups are very large - in one case over 100 [students]."

The inspectors concluded that insufficient progress was made in securing adequately experienced and qualified staff able to deliver consistently good teaching and learning.

The college had been rated satisfactory at its inspection in January last year, but at the monitoring visit in September it failed on all counts. Inspectors judged the college to be making insufficient progress in student achievement, quality of provision and leadership, and management.

On the college's website, Hindmarch explains that he introduced the radical restructuring plan to address the fact that in 2006, 36% of the college's courses were below average. "The students who enrol on those courses deserve far more," he states. "We intend to make Harlow College a byword for excellence. We intend to make sure that every one of our courses is well above the national average.

"We also intend to make sure that our students achieve the highest possible grades, so our sights are set at more and more students getting distinctions and grade A results."

In an interview he gave last month to the local paper, the Harlow Star, he was reported as saying that the cost of the restructuring showed good value for money and the strategy was already showing dividends in approved attendance and retention rates. But he added: "We did not want as many leaving that did, and with more leaving, the costs inevitably went up."

In his open letter to the education minister, Edwards says: "The AS and A2 module results appear to have been far from satisfactory. Through no fault of their own, there are now youngsters at Harlow whose chances of getting university places have been severely damaged. I think that the time has come for a further public meeting. I also think that it is time for Bill Rammell to publicly call for Hindmarch's resignation."

Edwards, a former school governor, says he is a Harlow resident with a long-standing interest in education in the Essex town. He admits he takes a particular interest in the events at the college as his partner was one of the lecturers who lost her job last summer. He also admits that his evaluation of the A-level module results is based not on official analysis but on anecdotal evidence he has gathered from parents and students.

"It is strongly anticipated that the results will be down quite considerably on last year and the year before, a drop of around 10%," he says. "This view is reinforced by the fact of the college reportedly offering to pay for resits for all those who want to take them. This offer was made prior to the results being announced."

The college also faces legal actions. At least two former lecturers are planning to take their cases to industrial tribunal. And UCU has issued legal proceedings over the way that the redundancy process was conducted, which could lead to a group compensation claim by members - for which a figure of £500,000 has been mooted.

Both Rammell and UCU are keen to see a period of calm following the turmoil at Harlow since Hindmarch announced wholesale changes in the way the college is run. In March last year, the principal informed lecturing staff that they would have to reapply for their jobs, which were being reorganised into roles of principal tutor, senior tutor and tutor.

The lecturers deemed unsuitable for the new posts were made redundant, and those who did not want to sign up to the new arrangement left with compensation.

The move prompted five days of strikes and a series of public meetings, which were attended by Rammell. The education minister told Education Guardian this week that the interventions he instigated were improving the situation. "I was very concerned at the implementation of the new strategy at the college and its impact on staff and learners," he said.

Trouble brewing

UCU says it will be making no further comment while talks with the college are under arbitration. A working party, chaired by the Advisory, Conciliation and Arbitration Service, is examining workload under the new contracts and is due to report in May.

However, further trouble is brewing over the appointment of two new student governors. Debbie Sheridan, the clerk to the board, says they have already been elected and their appointments will be announced later this week. But Broad, whose mother was a lecturer at the college and was made redundant last summer, says: "What elections? I am not aware of any elections taking place. I have seen no posters and I do not know anyone who has voted.

"As president of the students' union I expected to be a student governor, but students have had no representation at all on the board since the previous student governors left last summer. "I was told that the management wanted school governors who would represent the student body as a whole, rather than a small minority. I took that to mean those who did not like what Colin Hindmarch was doing to the college, but in reality that is the majority. I will be contacting the national union for advice about what can be done."

Hindmarch did not respond to repeated requests to be interviewed. His PA said: "He is in back-to-back meetings."